Because the elastoplascic tension character of the Continuously Reinforced Concrete Approach Pavement (CRCAP) is sensitive to the seismic response of the Fully Jointless Semi-integral Bridges (FJSBs), a macro elastoplastic tension-deformation theoretical model(P-Δ model) of CRCAP was developed from the uniaxial tensile average stress-strain constitutive model of the steel bar and concrete and a tensile test was carried out by using a full scale experimental model of CRCAP with a length of 28 m.Results show that: the theoretical skeleton curve is in good agreement with the tested curve,whatever the steel bar is pre-yield or post-yield and the CRCAP is still not broken when its tensile deformation reaches up to 14 cm. Conclusion is that the theoretical skeleton P-Δ model can be used for the seismic design and the damage assessment of FJSBs and the high ductility of the CRCAP is helpful for the FJSBs to resist strong earthquakes.